how difficult is pledging for each fraternity?

The general rule is the better the tier the harder they are going to make you work to get it. There are some exceptions like Pike and Sigma Pi’s are Pretty brutal.

Fraternities are different than sororities for this reason,pledging is just a much more difficult process. In the upper middle to top tier you will work so expect late nights, early mornings, over 100 hours of volunteering for formal and informal events, traditions, grueling library hours and 100% dedication to philanthropies and fundraisers. You will sacrifice a lot of your time and also be required to maintain a GPA higher than the rest of campus while meeting your financial requirements. It will be hard but worth it. Lower middle and bottom tier don't expect a whole lot of requirements or reward. Pi Kapp and tke excepted.